The present invention pertains generally to guidance seekers for spinning projectiles and specifically to a guidance seeker utilizing a reticle for determining the instantaneous target location relative to the projectile""s spin axis.
The present invention is related to applicant""s U.S. Pat. No. 5,529,262, which is hereby incorporated by reference. The present invention is also related to provisional applications, Ser. Nos. 60/034,006 and 60/047,476; filed Jan. 2, 1997 and May 23, 1997, respectively, which are incorporated herein by reference.
It is an object of the present invention to provide a guidance seeker for spinning projectiles that uses the projectile inertial properties as a guidance reference.
It is another object of the present invention to provide a guidance seeker with no moving parts.
It is still another object of the present invention to provide a guidance seeker of relatively very low cost, and small size and weight realization, thereby making it particularly suitable for very small caliber spinning projectile applications.
It is another object of the present invention to provide a guidance seeker for spinning projectiles that can be implemented together with all necessary electronic circuitry on a single silicon chip.
It is yet another object of the present invention to provide a guidance seeker that is suitable for a wide variety of small projectile applications, from handgun projectiles to artillery to small tactical missiles.
In summary, the present invention provides a reticle for a guidance seeker for a spinning projectile comprising a substrate for being secured stationary with the spinning projectile; a pattern of a plurality of alternating light modulating structures, such as opaque or light absorbing and light transmitting or light reflecting areas respectively on the substrate, such that an image of a target moving on the substrate in a cyclical fashion will generate (1) a plurality of pulses corresponding to the number of such light transmitting or light reflecting areas crossed by the image, the number of pulses increasing over the spin cycle as the image moves outwardly from the center of the reticle; and (2) the pulse lengths and/or the interstitial time periods between pulses vary in a unique, distinguishable, unambiguous, and singly periodic fashion during the spin cycle. Opaque and light transmitting pertain to refractive optics realizations, while light absorbing and light reflecting pertain to reflective optics. Both embodiments are essentially equivalent in principle, but one or the other may be more advantageous for realization depending on the spectral region of operation.
These and other objects of the present invention will become apparent from the following detailed description.